Klar A J
Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724.
Genes Dev. 1987 Dec;1(10):1059-64. doi: 10.1101/gad.1.10.1059.
The Saccharomyces cerevisiae HO gene, which encodes a site-specific endonuclease, is transcribed in the parent (mother) cell but not in the daughter (bud) cell. Consequently mother cells can switch their mating type whereas bud cells cannot. Whether or not the different capabilities of these cells are due to a nonrandom segregation of parental HO gene DNA strands to progeny cells is tested here by assaying the pattern of switching in cells where the HO gene is inverted in the chromosome. In an inverted HO strain, as is the case with the normal HO arrangement strains, only the mother cells were found to switch. Thus, the possibility of asymmetric segregation of parental HO gene DNA strands does not regulate the mother-daughter asymmetry of switching.
酿酒酵母的HO基因编码一种位点特异性内切核酸酶，该基因在亲代（母）细胞中表达，而在子代（芽）细胞中不表达。因此，母细胞能够转换其交配型，而芽细胞则不能。本文通过检测HO基因在染色体上发生倒置的细胞中的转换模式，来检验这些细胞的不同能力是否归因于亲代HO基因DNA链向子代细胞的非随机分离。在HO基因倒置的菌株中，与正常HO排列的菌株一样，仅发现母细胞能够转换。因此，亲代HO基因DNA链不对称分离的可能性并不调控转换的母-子不对称性。
